1. Field of the Invention
The present invention relates to a plant information display method, etc. for displaying elements regarding a plant in a tree view of hierarchical representation, and more particularly to a plant information display method, etc. that can display elements regarding a plant in a variety of representations.
2. Description of the Related Art
In control of a plant, there are many measurement points as measurement targets (hereinafter referred to as “items”) to properly perform control and analyses. An item ID, i.e., an identifier for accessing an item is uniquely assigned to each item in a system so that a user can individually access those many items. When the user accesses data in the plant, the user executes the data access (read and write) by designating the item ID. However, it is practically difficult for the user to keep all the item IDs in mind. Prior to designating the item ID, therefore, the user has to search for the item ID of the target item.
When there are items in so many numbers as that the user cannot keep the item IDs in mind, a tree view represented in a user interface of a computer is generally used as a scheme for searching the item IDs. The tree view enables the many item IDs to be displayed with grouping. Upon the user selecting, from a group list represented in the tree view, a group to which the objective item belongs, a list of items belonging to the selected group can be displayed.
Furthermore, the grouping of items in the tree view may be set in plural stages instead of one stage. In the former case, the user can search for the objective item ID by successively repeating selection of a group, to which the objective item belongs, from the grouping in plural stages, which are represented in the tree view. (See, e.g., Japanese Unexamined Patent Application Publication No. 2005-346444).
FIG. 7 illustrates a tree view in accordance with the plant hierarchical structure of ISA S95. In FIG. 7, for the sake of simplification, “Process Cell” is illustrated as a top level node with omission of “Enterprise”, “Site” and “Area”.
In FIG. 7, starting from the top in order, “Process Cell 01” is a node at an uppermost position in the illustrated tree structure, and “Unit 01” is a node for grouping items under “Process Cell 01”. Furthermore, “Tank 01” is a node indicating a first tank bound to “Unit 01”. “Temperature” is a node bound to an item ID representing a state (temperature) of “Tank 01”, and “Level” is a node bound to an item ID representing a state (level) of “Tank 01”. “Pump 01” is a node representing a pump bound to “Tank 01”, “Flow Rate” is a node bound to an item ID representing a state (flow rate) of “Pump 01”, and “Setting Value” is a node bound to an item ID representing a state (setting value) of “Pump 01”. “Valve 01” is a node representing a valve bound to “Tank 01”, “Opening Degree” is a node bound to an item ID representing a state (opening degree) of “Valve 01”, and “Setting Value” is a node bound to an item ID representing a state (setting value) of “Valve 01”. “Tank 02” is a node indicating a second tank bound to “Unit 01”, and “Unit 02” is a node for further grouping other items under “Process Cell 01”.
It is to be noted that a hierarchy under “Tank 02” and a hierarchy under “Unit 02” are omitted from the drawing.
Manipulations performed by the user when measuring the opening degree of “Valve 01” are described below. Premised user conditions are as follows: (1) the user does not keep in mind the item ID for accessing the opening degree of “Valve 01”, (2) the user understands to which “Unit” in the plant “Tank 01” is bound, and can select, from a “Unit” list, a relevant “Unit” to which “Tank 01” is bound, (3) the user understands to which “Tank” in the plant “Valve 01” is bound, and can select, from a “list of Tanks bound to Unit”, a relevant “Tank” to which “Valve 01” is bound, and (4) the user understands the structure of data held by “Valve 01” and can select, from a list of item IDs bound to “Valve 01”, a node of “Opening Degree” representing the objective item ID.
Manipulation procedures performed by the user and operations corresponding to the manipulation procedures are described below.
(1) First, the user performs a manipulation to display the tree view representing the plant hierarchy. With that manipulation, “Process Cell 01” is displayed as a “Top” node. At this time, the node of “Process Cell 01” is in a closed state, and children (“Unit 01” and “Unit 02”) of “Process Cell 01” are not displayed.
(2) Then, the user selects and spreads the node of “Process Cell 01”. With that manipulation, the node of “Process Cell 01” is opened, and the children “Unit 01” and “Unit 02” are displayed. At this time, the node of “Unit 01” is in a closed state, and the children (“Tank 01” and “Tank 02”) of “Unit 01” are not displayed. The node of “Unit 02” is also in a closed state, and the children (not illustrated) of “Unit 02” are not displayed.
(3) The user selects and spreads the node of “Unit 01” to which the objective pump is supposed to be bound. With that manipulation, the node of “Unit 01” is opened, and the children “Tank 01” and “Tank 02” are displayed. At this time, the node of “Tank 01” is in a closed state, and the children (“Pump 01” and “Valve 01”) of “Tank 01” are not displayed. The node of “Tank 02” is also in a closed state, and the children (not illustrated) of “Tank 02” are not displayed.
(4) The user selects and spreads the node of “Tank 01” to which the objective pump is supposed to be bound. With that manipulation, the node of “Tank 01” is opened, and the children “Pump 01” and “Valve 01” are displayed. At this time, the node of “Pump 01” is in a closed state, and the children (“Flow Rate” and “Setting Value”) of “Pump 01” are not displayed. The node of “Valve 01” is also in a closed state, and the children (“Opening Degree” and “Setting Value”) of “Valve 01” are not displayed.
(5) The user selects and spreads the node of “Valve 01” that is the objective device. With that manipulation, the node of “Valve 01” is opened, and the children “Opening Degree” and “Setting Value” are displayed.
(6) The user finds the node of “Opening Degree” that is the objective item.
In the related-art tree view, all the items are arranged on one tree view. Parent nodes and child nodes in the tree view are related to each other by binding them based on particular information. The particular information includes, for example:
(1) Information based on physical connections in terms of equipment and devices, and
(2) Information binding, as children, devices operated in production activity at the same time, i.e., as accessories belonging to the production activity (parent).
In the above-described specifications specifying the tree view, there occurs no confusion when all the items can be represented in an orderly way using only the tree structure (e.g., in the form of plant hierarchy). However, when a loop is generated in relation between items instead of being in the hierarchical relation in the tree, e.g., when loop gauges that are important in trying to look at the plant from the viewpoint of control are to be indicated in the plant hierarchy, such a relation cannot be represented properly.